Dania Ramirez was born in in Santo Domingo. She discovered by a modelling scout while working in a New York City convenience store at the age of 15, and was cast in a small part in a soda commercial. Years later, after completeing a degree at Montclair State University in New Jersey, she moved to Los Angeles. After working as an extra in the HBO film Subway Stories (1997), she met filmmaker Spike Lee who cast her in his film, 25th Hour (2003).

She appeared as Potential Slayer Caridad in the final episodes of the television series Buffy the Vampire Slayer, and as Callisto in the comic book film X-Men: The Last Stand (2006).